Novel about utopian society vs. authoritarian society

It's a short story not a novel. Art in the War Zone by Pat Murphy. I read it in Universe 14 edited by Terry Carr.

The sentry lit a cigarette. The flame cast a brief light on his face. He was young; he looked tired. Jax sympathized, just then, with Danny-boy and his insistence on minimal violence. She was glad she did not have to kill this youngster. He could have been one of her brothers, drafted to fight in a war. He did not deserve to die for that.

Jax slipped the dart into the blowgun and aimed at his neck, just above the collar of his shirt. She preferred the blowgun to the tranquilizer rifle; it was quieter and just as effective. She fired and ducked farther back in the shadows when he grabbed his neck. He was fumbling for his rifle, starting to lift it as the tranquilizer took effect, and he fell. He was down.

She stepped from the shadows and laid him carefully on his back. She crossed his arms neatly on his chest and snapped open the pouch of indelible skin paints that she carried on her belt. With her left hand she brushed the hair away from his forehead. She worked quickly and carefully, using the red paint and the black. Simplicity, she felt, was best at this point. In bold lettering across his forehead, she wrote dead in red. On his right cheek with black paint, she signed by jax. Between his folded hands she placed the death certificate, written by Danny-boy and lettered by Animal, a skilled calligrapher. The paper said:

Certificate of Death
Please consider yourself removed from combat.
Look at it this way—we could have killed you.
If you don’t quit fighting, we will.
Signed,
Danny-boy
War Chief
Artists Collective